Merge:
Now that we have the awesome feature that we can select several patterns at the same time, it could be handy some time to be able to merge them into one singel pattern, off course in the range of 1024 which is the max rows allowed in the mptm-format.

Split:
Sometimes you may have a too large pattern, maybe the same melody twice and it would a big timesaver if you could automatically split a pattern in half, instead of using copy/paste/delete.

Implemented in r12015 (thanks to JoaoBaptMG for the initial implementation submitted via GitHub). Merging is now possible from the order list context menu, as envisioned in your screenshot. Splitting a pattern is possible from the pattern context menu. It's split at the row where you right-click the pattern. If invoked via a keyboard shortcut, it's split at the edit cursor position instead.